Nasogastric Feeding
* May be used when a patient is unable or unwilling to ingest an adequate balanced diet orally.
* Gives an effective method of providing dietary supplements or total nutritional support.
* The patient must have an intact, functional gastrointestinal tract. If this is not the case parental feeding may be indicated.
Indications
* In order to give medication in patients unable to take oral preparations eg. in terminal care.
* Obstruction in the upper gastrointestinal tract which prevents normal ingestion, eg. in oesophageal carcinoma or stricture.
* Cases of dysphagia, caused by such conditions as motor neuron disease or cerebral tumours, where the quality of life is otherwise good.
* Cases of fistula when food taken orally may be aspirated.
* To improve overall nutritional status when a patient is too weak to eat adequate calories, eg. malabsorption syndromes.
* In conditions where discomfort or ulceration effects eating, such as following facial or oral surgery and during radiotherapy.
Administration of Feeds
* Feeds may be given by interupted bolus, or by controlled continuous drip using gravity or pumps.
* Bolus feeding is usually more convenient in the community because the patient spends less time connected to the feeding system. Feeding regimes can be tailored to an individuals life style, permitting freedom of movement in between feeds.
* A regime which is not compatible with an individual may generate such symptoms as nausea, vomiting, abdominal distension and discomfort.
* Gravity feeding can limit mobility within the home as the feeding container must be above the patient on a "drip stand".
* Undesirable side effects may be minimised and absorption maximised by using a pump controlled infusion. If an individual finds this too restrictive feeds may be administered over night.
Safe Practice
* It is essential to ensure the tube is actually in the stomach before commencing each feed, there are three ways this may be done.
a. aspirate some material and test it`s acidity using litmus, the hydrochloric acid in the stomach will turn blue litmus paper red.
b. Inject 5 mls of air down the tube while listening over the stomach with a stethoscope, a characteristic "rumbling" sound should be heard.
c. Radio-opaque tubes may be checked using X ray if this is felt necessary. This may be particularly relevant in cases where a fistula is present.
* If any change is observed in the patients respiratory status during feeding administration should be stopped at once and the position of the tube re-checked.
Aspects to Consider in Home Enteral Nutrition
* If all the diet is taken via the naso-gastric route, dietetic advice should be taken and the patients condition regularly assessed.
* Nutritional status may be monitored by recording intake and regular monitoring of weight. Other body measurements may also be recorded such as skin fold thickness and upper arm circumference, (so called anthropometric measurements).
* Tolerance to therapy should be monitored, this should include observation and recording of nausea and vomiting, diarrhoea or constipation. The psychological tolerance should also be closely observed.
* Vitamin and mineral status should always be remembered.
* Blood chemistry may be monitored for urea and electrolytes and the urine tested for blood and glucose.
Management Principles
* Pay attention to oral, nasal and skin hygiene. Tubes may chafe on the nasal vestibule (the front part of the nasal cavity which contain hairs) causing ulceration and possible skin infection. This area should therefore receive regular inspection and cleansing. Vaseline may be applied to promote comfort.
* Excessive crusting within the nose which may complicate radiotherapy can be softened with 25% glucose in glycerol drops eight hourly. Secretions and crusts can then be loosened with steam inhalations.
* Poor oral hygiene may result in mouth infections so it is important to keep the mouth hydrated. Regular washouts and care of teeth and dentures assists in moistening the mouth and reduces the build up of debris. Oral hydration may be aided by use of artificial saliva and by sucking ice cubes. Vaseline may be used to keep the lips moist.
* The tube should be secured to the side of the face using hypo-allergic tape. This should be done as unobtrusively as possible, particularly when the patient wants to go out. The end of the tube can be tucked over behind the ear when moving around.
* Patient and carer education should include management principles of feeding how and how to renew their supply of feeds. Pharmacists and enteral feed producing companies will normally deliver feeds directly to the home. Most manufactures also employ a pump loan scheme. Appropriate education will maximise patient independence.
* Eating is a social and emotional experience as well as a physiological necessity. For this reason it may be beneficial if a patient can have feeds at the same time the family takes a meal. This promotes a normal social interaction within the home.
* Some patients may benefit from chewing and spiting out of normal food, this may alleviate a "food depravation syndrome"
Administration of a Bolus Feed
* The temperature at which a tube feed may be administered varies from cold to hot. Administration of cold feeds has only a minimal effect on gastric emptying. Bolus feeds should be given at approximately 37`C
* The tube position is checked to ensure it is in the stomach.
* The feed may be run in by gravity or a 50 ml syringe used to apply gentle pressure to push the feed into the stomach.
* After feeding the tube should be rinsed through using water to prevent stasis of feed in the tube which would become infected.
* The tube should be sphigoted off after the feed.
* Drugs and feed should not be mixed but given separately. Where possible drugs should be given in aqueous solutions.
* Tubes may be left in situ for several months, if required and tolerated, before they need to be changed.
* If the tube becomes blocked or appears no longer to be in the stomach the tube should be replaced. If radiological checking is required the patient should be referred back to the hospital.
Complications of Tube Feeding
* Nausea and vomiting,
- Give smaller feeds and consider using antiemetics.
* Gastric reflux and aspiration,
- Feed with the patient in an upright position.
- Avoid night feeds.
- Check residual volumes in the stomach prior to feeding, if these exceed 75-100 mls then re-assess feed volumes.
* Constipation,
- Introduce a fibre containing feed and ensure adequate systemic hydration. Encourage patient mobility. If these measures fail consider laxative use.
* Diarrhoea,
- Try to identify the cause, these may include infection and antibiotic use.
- Feed volumes may be reduced.
- Intestinal osmolarity may be reduced by use of isotonic feeds.
- Lactose free feed may be tried.
- Pectin may be added to the feed.
- Anti-diarrhoeal medication may be considered if other measures fail.
After this you should:
* Be aware of the nursing skills involved in caring for a patient receiving nasogastric feeds.
* Reecognise possible complications associated with tube feeding and suggest remedies.
* Discuss the importance of ensuring correct tube position prior to feeding and carry out this check safely.
* Be able to offer appropriate patient education to individuals undergoing enteral nutrition.
* Be more aware of the nutritional status of your patients.
Further
Holmes S. (1992), Enteral Feeding, Community Outlook, 2 (10) 15-18.
Williams K.R. (1975), Effects of Temperature of Tube Feeding on Gastric Mobility of Monkeys, Nursing Research, 24 4-9
Saunders EH. Havener WH. Carol
FK. Gail H. (1979), Nursing Care in Eye, Ear, Nose and Throat Disorders, CV.
Mosby Co.,
Passing a Naso-gastric tube
Definition
* The passing of a flexible hollow tube via the nose, naso-pharynx and oesophagus into the stomach.
Indications
* Gastric decompression to prevent nausea, vomiting and gastric distension, eg. post operatively.
* Assessment of fluid loss from the upper gastro- intestinal tract and removal of stomach contents for analysis.
* Feeding in any condition where the patient is unable to ingest an adequate balanced diet, medication may also be given, eg. dysphagia in motor neurone disease or terminal care.
When to refer
* Oesophageal strictures or, fistula or varices.
* Nasal polyps or deviated septum, (which may haemorrhage).
* History of epistaxis.
* Oro-pharyngeal, oesophageal or gastric carcinomas.
* After laryngectomy, or other recent nose or throat surgery.
* Very anxious patients who may need sedation.
Equipment required
* Clinically clean tray
* The naso-gastric tube and guide wire. (If no guide wire is being used, the tube can be stiffened by pre-cooling, making it easier to pass).
* Gauze swabs and lubricant
* Hypo-allergenic tape
* 20 or 50 ml syringe
* Blue litmus paper
* Receiver
* Spigot or drainage bag and tubing, safety pin
* Glass of water
* Stethoscope
Measurement
* Ensure the correct length of tube by measuring the distance from the bridge of the nose to the bottom of the xiphoid process. Add to this the distance from the patients earlobe to the bridge of the nose, these combined distances will cause the tip of the tube to enter the stomach.
* Select the appropriate bore size, narrow for feeding, wider for aspiration. Narrow feeding tubes usually contain a guide wire to aid insertion.
Procedure for passing
* Ensure the full cooperation and understanding of the patient. Arrange a signal with the patient, such as raising a hand, so he or she can communicate if they want the procedure to stop.
* Assist the patient to sit in a semi-upright position,
support the head with pillows so it is not tilted back or forward.
* Lubricate the end of the tube by wetting it or use a water based lubricant.
* Ask the patient to blow his or her nose then check nostril patency by asking the patient to sniff.
* Pass the tube along the floor of the nose, the direction should be down and back, not up. If any resistance is encountered withdraw the tube slightly and try again in a slightly different position.
* As the tube passes through the nasopharynx into the oral-pharyx the patient should be asked to swallow so the tip of the tube passes the glottis into the oesophagus. The patient may be given a glass of water to aid swallowing.
* Continue passing the tube until the previously measured distance mark is reached.
* If a guidewire has been used this should now be removed using gentle traction.
* The tube should be spigoted, or for continuous drainage, attached to a closed bag. If a drainage bag is used, the associated tubing should be secured to the patients clothing using a safety pin to prevent accidental removal.
* The tube should be secured to a convenient place on the nose, side of the face or forehead. Hypo-allergenic adhesives should be used. To secure to the nose a one inch wide piece of tape, three inches long is split in half for 1 inches. The unsplit end is placed down the ridge of the nose. The split ends are wrapped alternately about the tube. Another 1 inch length may be placed over the first piece to give additional security.
* It is essential to ensure the tube is actually in the stomach, there are three ways this may be done.
a. aspirate some material and test its acidity using litmus, the hydrochloric acid in the stomach will turn blue litmus paper red.
b. Inject 5 mls of air down the tube while listening over the stomach with a stethoscope, a characteristic "rumbling" sound should be heard.
c. Radio-opaque tubes may be checked using X ray if this is felt necessary.
* If any change is observed in the patients respiratory status during insertion the tube should be withdrawn.
Management
Principles
* Pay attention to oral, nasal and skin hygiene. Tubes may rub on the nasal vestibule (the front part of the nasal cavity which contain hairs) causing ulceration and possible infection of hair follicles, this area should therefore receive regular inspection. Guard against irritation by acidic gastric fluids by keeping the skin clean, barrier creams may also be employed.
* Gastric contents may be aspirated using a 50 ml syringe. The patient should be semi-recumbant to reduce the possibility of the tube lying against the stomach wall. Suction should be gentle to avoid drawing in soft tissues.
* The volume and characteristics of aspirate should be noted and recorded, attention should be paid to fluid and electrolyte balance.
During feeding
* Prior to feeding the position of the tube should be checked by litmus testing of aspirate. Feeding may be carried out continuously or intermittently, depending on patient preferences and clinical requirements. A very fine tube may be used to minimise patient discomfort and a high energy well balanced diet can be given. Pumps are often used to aid administration. After feeding the tube should be rinsed through using water to prevent stasis of feed in the tube which would become infected.
* If all the diet is taken via the naso-gastric route, dietetic advice should be taken and the patients condition regularly assessed. In addition blood biochemistry should be monitored.
* Maximise patient independence by giving instruction of tube care, hygiene, feeding and in selected patients, tube replacement.
Removal
* Tubes may be left in situ for several months if required and tolerated.
* Nip off the end of the tube to prevent fluid running out during removal, withdraw gently and quickly while the patient holds his breath, these techniques reduce the possibility of aspiration.
After reading this you should be able to,
* Discuss the indications for passing a Naso-gastric tube.
* List the nursing skills involved in passing a naso- gastric tube.
* Describe the nursing care of a patient with a naso- gastric tube.
* Practice with greater confidence.
Further reading
Saunders EH. Havener WH. Carol
FK. Gail H. (1979), Nursing Care in Eye, Ear, Nose and Throat Disorders, CV.
Mosby Co.,